I'm have a slightly rough idle, feels like when the AC kicks on in a 4 cylinder and loads te engine down. I have two lean codes, one for each side, and I'm fairly positive its my cheap MAF sensor that's reading wrong. With the vehicle off and in run it shows 5.6gph on my Torque app. At idle I see anywhere from 4.xx-6.xx gph depending on engine temp/rpm.

Could you lease check what yours is showing at idke and also turned off in run. Just want to put the last nail in the coffin so to speak,.

 

Don't depend on that set of readings. You need to look a little more for the cause of your rich codes, by the way, what are the actual fault code numbers?
Usually if the MAF is bad you need a 733 or 734 tranny fault code or a 100 to 105 MAF also.

 

Changed the original post. Lean codes... 1171 and 1174. My O2's are showing rich though from my understanding. They are switching, but they are switching with a high voltage of .7-.8.

O2's are new Bosch; MAF is a new cheap eBay one. I replaced the O2's because they both through circuit codes and one had a bad heater code. The MAF was replaced due to a MAF and CAN Bus Code (can't remember which, but a common one to get thrown with the MAF sensor).

 

Engine Code: p1171

Land Rover Engine Code: P1171 = Lean Fueling Fault

Click to Process more Land Rover Engine Codes here

Engine Code: p1174

Land Rover Engine Code: P1174 = System too rich (bank 2) Additive injector adaptive fuelling - rich limit exceeded RH bank.

Click to Process more Land Rover Engine Codes here

Lean and rich..
???

I would put in injector cleaner.

 

I don't understand either

 

1171 is a global fault saying lean on both sides and 1174 says rich on just bank 2?

 

OK - seal up everything AFTER the MAF..
Did some digging for you.




I checked the box, filter, o-ring (inside the box pipe). I cleaned it all (the filter is new) and re-seated everything. I smeared some vaseline on the o-ring, and put some cable ties where the broken latch is. There are too many obstructions around the box and box/MAF joint to use duct tape, so I'm running it now to see if these adjustments have any effect. I'll let you know in a half an hour. I did notice there's a little flex/vibration at the box/MAF joint, but it seemed tight. If this doesn't do it, I might put something a little extra foam material around the air filter to make sure it is sealed all the way around. I can't see inside there to know if it's tight everywhere.


Found this on a competing blog

ECHNICAL INFORMATION TECHNICAL INFORMATION
MIL Event from Mass Air Flow Sensor

No: 19/03/01/NAS
Ref:
Issue: 1
Date: 07/13/01
AFFECTED VEHICLE RANGE:

Range Rover (LP) From XA410504 - All Bosch EMS
Discovery Series II (LT) All
SITUATION:
MIL ILLUMINATION: FAULT CODES INDICATE MASS AIR FLOW SENSOR PROBLEMS
Unfastened clips, improper sealing or incorrect filter installation can allow unfiltered air and dirt into
the intake. This uncontrolled air flow can result in MIL illumination and Mass Air Flow (MAF) adaption
faults and eventually to sensor contamination.
RESOLUTION:
PROPER INSTALLATION OF FILTERS AND SEALS
Correct maintenance of the air intake system includes the replacement of the air filter in compliance
with the maintenance schedule. More frequent replacement may be required in extreme use
conditions, such as deep water wading or desert driving.
Whenever the filter is replaced, careful execution of the replacement installation is required. It is
particularly important that the air filter box cover and locking clips are fitted correctly after the air filter
element has been changed. It is also possible for the ‘O’ ring seal between the air filter box and the
MAF sensor housing to be damaged during the filter change.
PARTS INFORMATION:
Range Rover
PHB102260.............Air Filter Housing Assy. Qty 1
· ESR4238...........Air Filter Qty 1
· PHN100220.......Seal Ring Qty 1
MHK100800 ............MAF Sensor Assy. Qty 1
Discovery Series II
ESR4237.................Air Filter Housing Qty 1
· ESR4238...........Air Filter Qty 1
· PHN100200.......Seal Ring Qty 1
ERR7171.................MAF Sensor Assy. Qty 1
Contaminated MAF components will require replacement.
WARRANTY CLAIMS:
Claim operation times for Air Filter replacement, MAF sensor replacement and Drive Cycle “C”
as appropriate.
Normal warranty policy and procedures apply.
Material allowance is included in labor operation.

TIB
19/03/01/NAS
CIRCULATE:
TO
Service Mgr
X
Warranty
X
Workshop
X
Body Shop
X
Parts
X
© Land Rover 2001 Page 1

TECHNICAL INFORMATION TECHNICAL INFORMATION
No: 19/03/01/NAS
REPAIR PROCEDURE
MIL INVESTIGATION AND AIR LEAK CORRECTION
1.
Investigation of a MIL event may reveal a range of
faults possibly related to uncontrolled air intake:
•
Fuelling adaptions codes (P0171, P0172,
P0174, P0175)
•
MAF sensor plausibility codes (P0101, P0102,
P0103)
•
Throttle angle plausibility codes.
CAUTION: It is important that the air filter
box cover and locking clips are fitted correctly
when the air filter element is changed. Care
must be taken to avoid damage to the O-ring
seal between the air filter and the MAF Sensor
during the filter change.
2.
Inspect the air filter housing for correct alignment
between the upper and lower portions.
3.
Inspect the O-ring to the MAF sensor for damage.
Figure 1
4.
If damage found, replace O-ring.
5.
If an uncontrolled air leak is determined, correct
the air leak as follows:
•
Clean the airbox of any foreign materials.
•
Refer to the Workshop Manual Section
19.10.10 and carefully install a new filter.
(Figure 1)
•
Verify proper fit of the cover to the filter
housing.
•
Install and latch the airbox cover. (Figure 2)
6.
If the filter housing cannot be correctly aligned to
the filter or the top cover, replace the filter
housing.
7.
Clear all P-codes.
8.
Allow vehicle to idle with the A/C off for 30 minutes to allow FRA/TRA adaptions to adjust.
9.
Check for P-Codes.
10. Perform Drive Cycle “C” to validate
11. If no P-codes are set during Drive Cycle “C,” the fault was in the filter installation. No additional
action is required.
NOTE: ONLY if plausibility P-codes are set during the drive cycle with a properly fitted filter
and a sealed airbox is MAF sensor contamination indicated as the root cause of the codes.
12. If P-codes are set, refer to the Workshop Manual Section 19.22.25 and replace the MAF sensor unit.
13. Install the filter and housing correctly to prevent uncontrolled air ingress.
14. Clear codes and verify repair by followings steps 8-10 above
Figure 2
PAGE 2 OF 2
© Land Rover 2001

would not attach as a pdf the file was too large.

 

Yea I just looked int he RAVE and they are both lean codes, one for each bank. I'll start looking for vacuum leaks. Thanks for the info JFALL.

1 out of 2 of the airbox top to MAF are broken. Never thought about that causing a lean though. I'll buy those parts instead of the MAF first.

 

Well messed around with it after work on Friday for 30 minutes or so. Left it run while listening for vacuum leaks. The only place I noticed is that I can hear it in the area of the IACV to Manifold hose. It changes sound if i put my hand over it. I did put a different hose on it and it collapsed completely, but the truck kept running. Makes me think that maybe there is a leak between the intake halfs, or maybe between the head/manifold.

The one thing I did find wierd was taht when watching the O2's when it's idling they were cycling up and down along with the fuel trim being 0-2%. So all looked well. After idling for a little while the O2 voltages dropped to next to nothing and the trim on both sides went to 25%. I'm wondering if there isn't some type of evap system (fuel tank or other) opening up and that's where my vacuum leak is.

I'm at a loss at the moment, but do not want to just throw parts. I think the first course of action will be to make myself a "smoke tester" and try that to find a leak.

 

I had these same codes. Had a cheap maf from the previous owner. Replaced with new correct MAF. All codes gone. I found a used one on eBay for 30$ just matched the part numbers. I remember being in yur shoes about 4 months ago. If its not the factory part number maf from bosch then its your problem. Frustrating.